EIP complexity assessment

EIP-7979: Call and Return Opcodes for the EVM

Assessed in Hegotá. The score describes the EIP text available at the snapshot, not the EIP as it stands today.

ProspectiveHegotáSnapshot 2026-08-25PFI at snapshotLayers: execution

LLM Completescore 16

Human Pending· No STEEL checklist existed on the ethspecs/pm default branch or in any open pull request at the snapshot.

LLM assessment

Evaluated on: 2026-08-26 · Spec revision: 2026-08-25 · ac450a4ab2 · Inclusion status at snapshot: PFI

Scope at the cutoff. Draft EIP-7979 execution-layer snapshot introducing CALLSUB, CALLDEST, and RETURNSUB, a bounded separate return stack, fixed opcode gas costs, and CALLDEST as a valid JUMP/JUMPI target. Opcode byte assignments remain undetermined. The assessment uses only package/eip.md and package/rubric.md.

16MediumMedium

Evaluator: LLMChecklist v2
Confidence: Medium
Under-specified at assessment cutoff: Yes — 2 criteria affected
Plausible range: 14–16 (Medium)
Snapshot: 2026-08-25 · EIP revision ac450a4ab2 (2026-08-25)

Score bands · Checklist revision 2

Low <12
Medium 12–22
High ≥23

28 criteria scored 0–3 (4 in exceptional cases; cross-EIP interactions is uncapped); nominal maximum 84.

Complexity profile

Each segment is one criterion's contribution to the LLM total. Hover or focus a segment for its score and rationale.

Under-specified at assessment cutoff: Yes

The EIP text available at the assessment cutoff left material behavior unresolved. The affected criteria and the plausible total range record that uncertainty.

Why: Final opcode byte assignments are absent, and the required initialization and lifetime boundaries of the return stack are not explicit. These gaps are material to canonical vectors and client agreement but localized to opcode/test baselining and return-stack semantics.

Plausible total

14–16
recorded score 16 · plausible tiers Medium

Affected criteria (2)

Patterns affecting pre-existing tests (1)
Unspecified behavior requiring cross-client consensus (2)

Unresolved questions at the cutoff (2)

Which byte values are assigned to CALLSUB, CALLDEST, and RETURNSUB?
Must each EVM machine instance initialize an empty return stack, and what are its exact lifetime boundaries across nested executions?

Notable ambiguities noted by the assessor (2)

The prose defines PC as the index of the next byte to execute while the algorithms and traces use PC as the current instruction position; the observable return target PC+1 is nevertheless clear from the tests.
The EIP calls the change backwards compatible while final opcode allocation—and therefore the exact pre-existing opcode-recognition vectors affected—remains unknown.

Criterion breakdown

EIP-7979 Hegotá: LLM criterion scores and rationale
Criterion	Score	Why this score	Evidence / uncertainty
Added opcodes	3	Multiple opcodes are added and at least CALLSUB and RETURNSUB have nontrivial cross-stack/control-flow mechanics, satisfying score 3.	eip.md · Abstract; Specification CALLSUB, CALLDEST, and RETURNSUB are three new instructions. eip.md · Specification > CALLSUB; Specification > RETURNSUB CALLSUB consumes a dynamic data-stack destination and pushes a bounded private return stack; RETURNSUB pops that separate stack into PC. Confidence: High Uncertainty: Opcode numbers are TBD, but the count and semantic complexity of the instructions are explicit.
Modified opcodes	3	The observable destination-validity behavior of pre-existing JUMP and JUMPI is modified, so the rubric's binary score 3 applies.	eip.md · Specification > CALLDEST CALLDEST is declared a valid destination for the existing JUMP and JUMPI opcodes. eip.md · Reference Implementation > get_valid_destinations; final paragraph Destination analysis adds every CALLDEST to valid jump destinations, changing the set consumed by JUMP and JUMPI even though their handlers need no edit. Confidence: High Uncertainty: The implementation location of the change is destination analysis rather than the opcode handlers, but the opcode result is still changed.
Edge/boundary conditions	3	There are multiple boundary-prone mechanisms, and the 1024-depth limit plus mixed CALLSUB/JUMP/JUMPI/RETURNSUB paths requires an elevated set of depth, destination, and exceptional-halt cases.	eip.md · Specification > CALLSUB; Specification > RETURNSUB Exceptional halts cover non-CALLDEST targets, return-stack depth 1024, and an empty return stack. eip.md · Test Cases > Failure 1; Failure 2; Subroutine at end of code Cases exercise an out-of-range target, return underflow, and return to the implicit STOP just past code. eip.md · Rationale > Why may JUMP land on a CALLDEST? Tail calls, mutual recursion, and jumps entering subroutines create distinct return-stack control-flow paths. Confidence: High Uncertainty: The exact opcode bytes are open, but that does not reduce the stated semantic boundary set.
Security risks	2	The mechanism touches a limited set of existing but security-sensitive EVM control-flow components and changes destination-validity assumptions, so it warrants targeted review and fuzzing rather than isolated validation alone.	eip.md · Security Considerations Safety depends on return-address isolation plus runtime checks for destination validity, underflow, and overflow. eip.md · Reference Implementation > get_valid_destinations; The three new instructions The mechanism interacts with code scanning, data-stack popping, gas charging, PC changes, exceptional halts, and the new return stack. Confidence: Medium Uncertainty: The EIP describes safety checks but provides no allowlisted implementation or fuzzing evidence.
Unspecified behavior requiring cross-client consensusUnder-specified	2	Canonical bytecode vectors cannot be baselined until clients agree on opcode assignments, and return-stack initialization/lifetime needs a localized consensus reading. These are localized agreements, not a broad redefinition of previously unobservable behavior.	eip.md · Specification > Notes Opcode values are explicitly still to be determined. eip.md · Test Cases > introductory note All bytecode tests use placeholder opcode assignments that must be confirmed. eip.md · Specification > opening paragraphs; Reference Implementation > Evm field addition A return stack is added to EVM machine state, but its required initialization and lifetime boundaries are not stated explicitly. Confidence: Medium Uncertainty: Implementation, devnet, and discussion status are unavailable by package policy, so this score uses the snapshot text alone.
EVM Gas rule changes	1	The opcode gas schedule is extended, but charging uses the existing fixed execution-gas mechanism and existing cost constants; no new metering mechanism is introduced.	eip.md · Specification > CALLSUB; Specification > CALLDEST; Specification > RETURNSUB The three instructions have fixed costs of mid (8), jumpdest (1), and low (5). eip.md · Reference Implementation > The three new instructions Each new handler charges an existing GAS_MID, GAS_JUMPDEST, or GAS_LOW constant. Confidence: High Uncertainty: The EIP says cost balance needs benchmarking, but the accounting form and proposed values are explicit.
Patterns affecting pre-existing testsUnder-specified	1	The change should affect only a minor fork-specific subset of existing invalid-opcode and destination-validation vectors once opcode bytes are allocated; the EIP does not indicate broad reworking of diverse existing tests.	eip.md · Backwards Compatibility The EIP says existing EVM code semantics do not change, subject to unspecified behavior. eip.md · Test Cases > introductory note Tests use placeholder bytes 0xB0-0xB2 because final opcode assignments are not confirmed. Confidence: Medium Uncertainty: The exact pre-existing vectors affected cannot be identified until the opcode bytes are assigned.
Performance risks	1	The new opcode paths and return-stack operations require validation, but they can be benchmarked in isolation and existing bytecode behavior is stated unchanged.	eip.md · Specification > Costs The EIP explicitly says benchmarking is needed to determine whether the three fixed costs are balanced. eip.md · Rationale > Are there real-time performance gains? Performance claims are framed around control-flow workloads and compiler/interpreter execution paths. Confidence: Medium Uncertainty: The EIP cites asset benchmarks, but no supporting asset is allowlisted in this package; only the text's need for benchmarking is used.

Show 20 zero-score criteria

Zero-score criteria (Checklist revision 2)
Criterion	Why this score	Evidence / uncertainty
Added precompiles	No precompile is introduced.	eip.md · Abstract; Specification Only EVM instructions are added. Uncertainty: None; precompiles are absent from the proposal.
Modified precompiles	No precompile logic or gas schedule is modified.	eip.md · Specification; Backwards Compatibility The change is confined to new control-flow instructions and does not alter existing EVM code semantics. Uncertainty: None; no precompile is identified.
Added system contracts	No system contract is introduced.	eip.md · Abstract; Specification The proposal introduces instructions and private per-execution machine state, not deployed code. Uncertainty: None; no contract address, code, state, or system action is specified.
Modified system contracts	No existing system contract code or state is directly or indirectly modified by the specified mechanism.	eip.md · Backwards Compatibility The proposal states that existing EVM code semantics are unchanged. Uncertainty: None; system contracts are not identified or targeted.
State-access ordering within opcode execution	No opcode adds, moves, or reorders a state access or a gas charge relative to state access.	eip.md · Specification The instructions manipulate only the data stack, return stack, and program counter. eip.md · Reference Implementation > The three new instructions The reference handlers contain no account, storage, or other state access. Uncertainty: None; the specified execution steps contain no state-access surface.
Blob gas accounting changes	No blob gas rule or blob-related mechanism is introduced or modified.	eip.md · Abstract; Specification The proposal is limited to three EVM control-flow instructions and their machine-state behavior. Uncertainty: None; blobs are outside the proposal's stated and normative scope.
State gas accounting changes	There is no state-gas charging site, state-byte rate, budget, reservoir, or spill-path change.	eip.md · Specification; Reference Implementation > The three new instructions The new operations change control flow and private machine state but do not write persistent state. Uncertainty: None; persistent-state writes and state-gas accounting are absent.
New EVM gas refund	No refund mechanism or interaction with existing refunds is specified.	eip.md · Specification > Costs; Reference Implementation > The three new instructions The proposal specifies only positive fixed gas charges for the three instructions. Uncertainty: None; the gas provisions contain no refund behavior.
New transaction types	No transaction type is introduced.	eip.md · Abstract; Specification The proposal changes EVM instruction execution only. Uncertainty: None; transactions are outside the normative change.
New or modified transaction validity mechanisms	No transaction validity rule or intrinsic gas calculation is added or modified.	eip.md · Specification; Backwards Compatibility The rules concern execution of three bytecode instructions and claim no change to existing EVM code semantics. Uncertainty: None; instruction exceptional halts are execution results, not transaction-validity changes.
New block / header fields	No block or block-header field is introduced.	eip.md · Specification The only new field is an internal EVM return stack. Uncertainty: None; the return stack is machine state, not a block field.
Encoding changes (RLP/SSZ)	Assigning opcode bytes is not an RLP/SSZ transaction, block, or interface encoding change under this anchor.	eip.md · Rationale > Why no immediate arguments or code sections? The design deliberately avoids immediate arguments and code sections that would increase instruction-encoding complexity. eip.md · Specification No transaction, block, or interface encoding is changed. Uncertainty: Final opcode byte values are open, but they do not create an encoding change in the anchor's stated scope.
Block syncing changes	No block RLP field or block-validation rule requiring sync testing is introduced.	eip.md · Abstract; Specification The entire normative change is inside EVM instruction execution. Uncertainty: None; block encoding and syncing are outside the specified scope.
New fork activation mechanism	No state or existing internal variable is modified specifically at the fork-activation block.	eip.md · Specification; Backwards Compatibility The proposal adds instruction semantics and new per-execution machine state without prescribing activation-block mutation. Uncertainty: Return-stack initialization is under-specified, but initialization of a new internal variable is excluded by this rubric anchor.
Engine API changes	No Engine API field, endpoint, or communication mechanism is introduced.	eip.md · Specification The specification adds EVM machine state and opcodes without any engine communication field or endpoint. Uncertainty: None; the Engine API is not part of the proposal.
Transition-tool interface changes	No transition-tool input, output, field, or fork-activation awareness mechanism is specified.	eip.md · Specification; Reference Implementation All specified inputs and effects are internal to EVM bytecode execution and machine state. Uncertainty: None; the package contains no transition-tool interface change.
New invariant on pre-existing tests	Tests unrelated to this EIP do not gain a new consensus-visible value or invariant to assert.	eip.md · Specification > Notes The return stack's actual state is not observable by EVM code and is stated not to be consensus-critical. eip.md · Backwards Compatibility The EIP states that existing EVM code semantics are unchanged. Uncertainty: None; internal return-stack representation is explicitly excluded from consensus observability.
New test-framework primitives	The specified behavior can be tested with existing bytecode execution, gas, and failure expectations; no new framework abstraction is required by the text.	eip.md · Test Cases The supplied cases are expressed as bytecode, execution traces, gas totals, and success or exceptional-halt outcomes. eip.md · Specification > Notes The return stack representation itself is not consensus-critical or EVM-observable. Uncertainty: No test-framework source is in the package; the score follows the behavioral form of the included tests.
Cryptography	No cryptographic primitive or cryptographic functionality is introduced or modified.	eip.md · Abstract; Specification The proposal adds control-flow labels, calls, returns, and a private return stack only. Uncertainty: None; cryptography is absent from the normative mechanism.
Cross-EIP interactions	The normative proposal is self-contained; named design comparisons and statements of non-preclusion do not establish a coordinated cross-EIP testing dependency.	eip.md · Backwards Compatibility The EIP says the change does not preclude EOF, RISC-V, or other changes. eip.md · Rationale > Why no immediate arguments or code sections? EVM Object Format is discussed as a complementary design comparison, not as a dependency, modification, or conflict. Uncertainty: No interacting EIP number or normative dependency is identified in the package.

Assessment provenance

Assessed EIP revision: ethereum/EIPs@ac450a4ab2 EIPS/eip-7979.md committed 2026-08-25 · information cutoff 2026-08-25T11:56:58Z
Current master · File history · blob 1276ae5354 · sha256 377407cd7342
Rubric: Checklist revision 2 · ethspecs/pm@3d8c0128c5
Evaluator: gpt-5.6-sol at xhigh reasoning effort · isolation bubblewrap_one_eip_capsule_v1
Source record: Frozen research record research/tasks/08-hegota-prospective-complexity-assessment/outputs/assessments/hegota-pfi-2026-08-26/eip-7979.yaml · sha256 a72e886bb5d2

Compare EIP-7979 with other assessments All Hegotá assessments

Criterion legend and glossary

Every stacked bar, comparison matrix, and criterion table on this site uses the same criterion colours, abbreviations, and order. Colour marks the criterion group; the abbreviation and name identify the criterion. Scores are 0–3 per criterion (4 is exceptional; cross-EIP interactions is uncapped).

EVM surface

Opcodes, precompiles, and system contracts that are added or modified.

OP+
Added opcodes
Introduces new opcodes
Score anchors
0
No new opcodes are introduced.
1
A new simple opcode is introduced (no data portion, no complex stack mechanics, and a constant gas cost).
2
Multiple new simple opcodes are introduced, or a single new complex opcode is introduced (has data portion, or complex stack mechanics, or a dynamic gas cost).
3
Multiple new opcodes are introduced, and at least one of them is complex (has data portion, or complex stack mechanics, or a dynamic gas cost).
- Cryptography opcodes are not considered complex by default. Refer to the "Cryptography" section for a separate assessment.
Modified opcodes
Modifies pre-existing opcodes
Score anchors
0
No pre-existing opcode modifications are introduced.
3
At least one pre-existing opcode's behavior is modified (not including gas changes) or a pre-existing opcode is deprecated.
PC+
Added precompiles
Introduces new precompiles
Score anchors
0
No new precompiles are introduced.
1
A new simple precompile is introduced (constant input length, constant gas cost).
2
Multiple new simple precompiles are introduced, or a single new complex precompile is introduced (dynamic input length or dynamic gas cost).
3
Multiple new precompiles are introduced, and at least one of them is complex (dynamic input length or dynamic gas cost).
- Cryptography precompiles are not considered complex by default. Refer to the "Cryptography" for a separate assessment.
Modified precompiles
Modifies pre-existing precompiles logic or gas-accounting
Score anchors
0
No pre-existing precompiles are modified.
1
At least one pre-existing precompile has its gas schedule modified.
2
Multiple pre-existing precompiles have their gas schedule modified, or a single pre-existing precompile has its behavior modified.
3
The behavior of multiple pre-existing precompiles, or a single complex pre-existing precompile modified.
Added system contracts
Introduces new system contract, stateful or not
Score anchors
0
No new system contracts are introduced.
1
A new system contract is introduced that is not stateful nor does it trigger a new system action (e.g. requests to the consensus layer).
2
Multiple new system contracts are introduced or a single new system contract that is either stateful or triggers a new system action (e.g. requests to the consensus layer).
3
Multiple new system contracts are introduced and at least one of them is either stateful or triggers a new system action (e.g. requests to the consensus layer).
Modified system contracts
Modifies pre-existing system contracts
Score anchors
0
No modifications to pre-existing system contracts are introduced, directly or indirectly.
1
Does not directly modify any system contract, but its behavior has minor indirect effects on one or more system contracts.
2
Does not directly modify any system contract, but its behavior has major indirect effects on one or more system contracts.
3
At least one pre-existing system contract code or state is modified, which would involve irregular state transition or a similarly complex transition methodology.

Gas and accounting

Execution, blob, and state gas rules, refunds, and where charges happen inside opcodes.

EVM Gas rule changes
New EVM gas accounting rules
Score anchors
0
No gas accounting changes.
1
Existing gas accounting mechanism is updated.
2
A new gas accounting mechanism is introduced but it does not affect existing mechanisms nor does it affect existing tests.
3
A new gas accounting mechanism is introduced and affects existing mechanisms which in turn affect existing tests.
ORD
State-access ordering within opcode execution · Checklist revision 2 only
Changes *where inside an opcode's execution* state is accessed, or where gas is charged relative to that access. Because a state access is recorded in the block-level access list only if execution had enough gas to reach it, this ordering is consensus-critical: moving it changes the BAL at every gas boundary of every affected opcode.
Score anchors
0
No change to where state is accessed, or to where gas is charged relative to a state access, within any opcode.
1
A single opcode's state-access or gas-charge ordering changes.
2
Multiple opcodes' ordering changes, or a new state-accessing operation is introduced whose position in the order must be settled.
3
The ordering rule changes for a whole class of state-accessing opcodes at once, or what counts as a recordable state access is redefined — requiring existing BAL vectors to be re-derived across opcodes and forks.
- Distinct from "Modified opcodes", which asks whether an opcode's **result** changed. This row asks about the **path to the result**, which is observable even when the result is identical. An EIP can be 0 on that row and 3 on this one.
- Score changes **to** the ordering. Do not score the fact that state accesses are observable — they always are.
- Each boundary must be re-tested against every other dimension that can change the answer (cold/warm, static/non-static, delegated/direct, revert/success), so the case count grows multiplicatively rather than additively. Note this explicitly under Special Considerations.
Blob gas accounting changes
New Blob gas accounting rules which potentially affect pre-existing tests
Score anchors
0
No blob gas accounting changes.
1
Existing blob gas accounting mechanism is updated.
2
A new blob gas accounting mechanism is introduced but it does not affect existing mechanisms nor does it affect existing tests.
3
A new blob gas accounting mechanism is introduced and affects existing mechanisms which in turn affect existing tests.
SGAS
State gas accounting changes · Checklist revision 2 only
New state gas accounting rules. State gas is the cost of *writing* state, as opposed to accessing or executing it: `StateGasCosts`, `COST_PER_STATE_BYTE`, the block-level state gas budget, and the spill path into execution gas.
Score anchors
0
No state gas accounting changes.
1
An existing state gas cost or `STATE_BYTES_PER_*` rate is adjusted.
2
A new state-gas-charging site is introduced, or the block-level state gas budget or reservoir allocation is modified.
3
A new state gas charging mechanism is introduced, or the spill interaction between state gas and execution gas is modified, affecting existing gas tests.
- Harder to test than blob gas: the spill path means state gas cannot be metered independently of execution gas, and some costs (e.g. `NEW_ACCOUNT`) are state-dependent.
New EVM gas refund
New gas-refund mechanism
Score anchors
0
No new gas-refund mechanisms are introduced.
1
A new simple gas-refund mechanism is introduced that does not affect either existing tests or existing gas-refund mechanisms.
2
A new complex gas-refund mechanism is introduced or a simple mechanism that affects existing tests or existing gas-refund mechanisms.
3
A new complex gas-refund mechanism is introduced that affects existing tests or existing gas-refund mechanisms.

Blocks, transactions, and encoding

Transaction types and validity, block and header fields, encodings, syncing, and activation-time changes.

New transaction types
Introduces a new transaction type
Score anchors
0
No new transaction types are introduced.
3
A new transaction type is introduced.
New or modified transaction validity mechanisms
Creates new or modifies pre-existing transaction types' validation mechanisms
Score anchors
0
No changes are introduced to the validity rules of existing transaction types or to their intrinsic gas cost calculation.
1
Minor adjustments are introduced to validity rules or intrinsic gas cost calculation, but they do not significantly affect existing tests.
2
Changes to validity rules or intrinsic gas cost calculation affect existing tests, but require only limited updates to test cases and no redesign of the testing infrastructure.
3
Changes to validity rules or intrinsic gas cost calculation require extensive rework or redesign of the tests or testing infrastructure.
New block / header fields
Introduces new block or block header fields
Score anchors
0
No new block or header fields are introduced.
3
A new block or header field is introduced.
ENC
Encoding changes (RLP/SSZ)
Introduces encoding changes at the transaction/block/interfaces level
Score anchors
0
No encoding changes are introduced at the transaction, block, or interfaces levels.
3
An encoding change is introduced at transaction, block or interfaces level (e.g. RLP -> SSZ).
- "Interfaces level" includes the Engine API. Score an Engine API encoding change (e.g. JSON -> SSZ) here.
Block syncing changes
Modifies block RLP validation mechanisms that require test client syncing.
Score anchors
0
No new RLP validation mechanism is introduced.
1
A single simple RLP validation mechanism is introduced.
2
Multiple simple RLP validation mechanisms are introduced or a single complex one.
3
Multiple RLP validation mechanisms are introduced and at least one of them is deemed complex.
ACT
New fork activation mechanism
Modifies state, internal variables, or similar, at the fork activation block
Score anchors
0
No state modifications, internal variables or similar are modified at the fork activation block.
3
Either a state modification or internal variables are modified at the fork activation block.
- Initialization of new internal variable is not considered a modification.

Client interfaces

Engine API and transition-tool interface changes.

Engine API changes
Introduces new fields to the Engine API directives
Score anchors
0
No new fields or communication mechanisms are introduced to the Engine API.
1
A single new field is introduced in one of the Engine API endpoints.
2
Multiple fields are introduced to one or multiple Engine API end points, or a new Engine API end-point is introduced.
3
Multiple fields are introduced to one or multiple Engine API end points and a new Engine API end-point is introduced.
Engine API encoding changes · Checklist revision 1 only
Engine API encoding changes (the revision-1 template defines no anchor text for this row).
T8N
Transition-tool interface changes
Modifies or adds new fields to the transition tool interface.
Score anchors
0
No modifications to the transition tool interface are required.
1
A single new field needs to be introduced to the transition tool interface.
2
Multiple new fields or a new mechanism has to be introduced to the transition tool interface.
3
Multiple new fields and a new mechanism has to be introduced to the transition tool interface.
- Special consideration must be paid to this section if the EIP introduces a mechanism that requires the state transition tool to be aware whether the block it is processing is the fork-activation block.

Testing impact

Rework, new invariants, and new primitives required in the test framework.

Patterns affecting pre-existing tests
Implements a new validation mechanism or rule that translates in reworking pre-existing tests
Score anchors
0
No pre-existing tests are affected by this change.
1
Minor subset of existing tests are affected by this change.
2
Considerable subset of existing tests are affected by this change but involves only a contrived category of tests.
3
Major subset of existing tests are affected, including diverse category of tests (benchmarks, static, multiple forks, etc.).
INV
New invariant on pre-existing tests · Checklist revision 2 only
Tests that are **not about this EIP** must nonetheless assert something this EIP produces. Their logic does not change; they gain a new thing to check.
Score anchors
0
Pre-existing tests assert nothing new.
1
A narrow, contrived category of pre-existing tests gains a new assertion.
2
A broad category gains a new assertion, applied mechanically.
3
Every test in the fork gains the assertion regardless of what it tests, and pre-fork vectors must be re-derived to satisfy it.
- Paired with the row above, and easy to confuse with it. "Patterns affecting pre-existing tests" asks whether existing tests must be **reworked**; this row asks whether they must **additionally assert something new**. Score both — an EIP can be low on one and high on the other.
New test-framework primitives · Checklist revision 2 only
Requires new abstractions in the test framework itself — expectation types, modifiers, helpers — beyond writing test functions with what already exists.
Score anchors
0
Existing test primitives suffice.
1
Existing primitives need minor extension.
2
New expectation or modifier primitives are required, reusable within this EIP's own test suite.
3
New framework-level primitives are required that become a permanent part of the framework and are used by other EIPs' tests.

Risk and validation

Security, performance, boundary conditions, and cryptography that need validation.

Security risks
Introduces or modifies mechanisms that could compromise the security of the chain, users, validators, or other stakeholders, if not implemented properly.
Score anchors
0
No new mechanisms are introduced that could pose a security risk.
1
The introduced mechanisms are self-contained, can be validated in isolation, and do not alter existing invariants that could pose a security risk for any stakeholders.
2
The introduced mechanisms interact with a limited number of existing components, slightly altering their security assumptions and requiring a targeted security review or fuzzing.
3
The introduced mechanisms interact with multiple existing components, including critical ones, substantially altering their security assumptions and requiring an extensive security review and fuzzing.
Performance risks
Introduces or modifies mechanisms and requires performance validation.
Score anchors
0
No new mechanisms are introduced that require performance validation.
1
The introduced mechanisms can be benchmarked in isolation and do not affect existing performance behavior.
2
The introduced mechanisms cannot be fully benchmarked in isolation, but they only have a limited impact on the existing performance benchmarks.
3
The introduced mechanisms cannot be benchmarked in isolation and have a substantial impact on existing performance benchmarks or have complex interactions with existing mechanisms.
Edge/boundary conditions
Feature contains edge/boundary conditions.
Score anchors
0
No discernible edge cases or boundary conditions are introduced.
1
A single edge-case or boundary-condition prone mechanism is introduced.
2
Multiple edge-case or boundary-condition prone mechanisms are introduced, but none of them requires an elevated number of cases to test.
3
Multiple edge-case or boundary-condition prone mechanisms are introduced and at least one of them requires an elevated number of cases to test.
Cryptography
Introduces new cryptography mechanisms or modifies existing functionality that involves cryptography
Score anchors
0
No cryptography mechanisms are introduced.
1
A new cryptography mechanism is introduced but it is a well known mechanism that is known to have vast resources to aid on its testing.
2
Multiple new cryptography mechanisms are introduced that are well-known or a single but novel mechanism is introduced that is either untested or has limited resources.
3
Multiple new cryptography mechanisms are introduced and at least one of them is a novel mechanism.

Coordination

Cross-EIP interactions and behavior that clients must agree on before tests exist.

XEIP
Cross-EIP interactions
Introduces or modifies mechanisms that affect other EIPs in either the same or past forks.
Score anchors
0
Fully self-contained EIP that does not depend on, modify, or conflict with any other EIP.
1
The EIP interacts with one or more other EIPs in a non-critical and limited way but can be tested independently for the most part.
2
The EIP depends on or modifies one or more other EIPs such that coordinated testing and consideration is required, but interactions are limited in scope and not complex.
3
The EIP has strong interdependencies with multiple EIPs, requiring extensive coordinated cross-EIP testing as well as potential re-design of existing test vectors.
- +1 for every 3 additional interacting EIPs beyond the first 3, each of which requires its own coordinated test cases. List the EIPs in the rationale.
- This row is intentionally uncapped, unlike every other anchor: each interacting EIP is another axis of the test matrix, so a ceiling would make a 12-EIP product indistinguishable from a 3-EIP one.
UNSP
Unspecified behavior requiring cross-client consensus · Checklist revision 2 only
The EIP text does not determine the answer for cases a test can construct. Clients must agree on a previously unspecified detail before tests can be baselined. The cost here is coordination and re-baselining, not test writing.
Score anchors
0
The EIP text determines the answer for every case a test could construct.
1
A few details are unspecified but have an obvious intended reading.
2
Details require client agreement before tests can be written, but they are localized.
3
A previously unspecified *and previously unobservable* behavior becomes consensus-critical; expect tests to be re-baselined on each round of EIP amendment.
- Score this from the EIP's state at assessment time: whether it has client implementations, whether it has been through a devnet, and how many open questions remain on its discussion thread.